Antimicrobial Resistance: High Rates of Resistant Bacteria Found Among Veterinarians

Veterinary clinic staff are believed to carry twice as many bacteria with antibiotic resistance, particularly those that cause the most common infections in healthcare facilities and communities. Close contact with animals appears to be the cause of this higher prevalence, according to a recent study conducted in the Netherlands. Developing effective preventive measures requires a better understanding of the significance of animal-to-human transmission.   Enterobacteriaceae are the most common causes of community-acquired and nosocomial infections. They are generally treated with beta-lactams (penicillins, cephalosporins, carbapenems) or fluoroquinolones. Over the past two decades, a significant increase in the resistance of Enterobacteriaceae to these antibiotics has been observed, particularly in Escherichia coli and Klebsiella pneumoniae. Both of these bacteria live in the intestines of healthy humans and animals. Although most strains are harmless, some can cause severe food poisoning and potentially life-threatening infections. In particular, they are responsible for more than 40,000 cases of blood poisoning each year in the United Kingdom. The fact that these bacteria acquire resistance genes encoding ESBLs or cyclic adenosine monophosphate (cAMP)—which give them the ability to hydrolyze, and thus resist a wide variety of penicillins and cephalosporins, is not to be taken lightly. Understanding the extent of transmission from animals to humans is essential for developing effective prevention strategies. Scientists at the National Institute for Public Health and the Environment in the Netherlands therefore studied the link between the spread of these bacteria and occupational contact with farm animals and pets. Fecal samples were collected from 482 staff members working in veterinary settings (including veterinary practitioners, as well as assistants and support staff). Genetic sequencing of their gut microbiota identified not only the bacterial species but also the associated resistance genes. The analysis revealed that nearly one in ten veterinary staff members (9.8%, 47 out of 482) were colonized by at least one bacterial strain with antibiotic resistance and the ability to produce ESBLs or c-peptidase, which is twice the rate seen in the general population (4.5%). Furthermore, veterinarians who had traveled to Africa, Asia, or Latin America in the past six months were four times more likely to carry bacteria with ESBL resistance genes. Similarly, those who had reported gastrointestinal symptoms in the past four weeks were twice as likely to be colonized by these resistant bacteria. This higher prevalence among veterinary staff cannot, therefore, be explained by known risk factors, such as antibiotic use or travel. According to the researchers, close contact between animal health professionals and animals appears to be responsible for the formation of a reservoir of ESBL-producing bacteria, leading to the shedding and transmission of multidrug-resistant pathogens to humans. Unfortunately, no samples were collected from animals visiting the clinics, which is a limitation of the study. To combat antimicrobial resistance, the authors emphasize the importance of reducing the inappropriate use of antibiotics in the treatment of animals, but above all of limiting transmission by enforcing strict hygiene standards.